Risk assessment of left ventricular systolic dysfunction in primary care: cross sectional study evaluating a range of diagnostic tests
- Olav Wendelboe Nielsen, research fellow (own{at}dadlnet.dk)a,
- Jørgen Fischer Hansen, chief consultanta,
- Jørgen Hilden, associate professorb,
- Carsten Toftager Larsen, registrara,
- Jens Svanegaard, registrarc
- a Cardiovascular Department, Copenhagen University Hospital Hvidovre, DK-2650 Hvidovre, Denmark
- b Department of Biostatistics, Panum Institute, Copenhagen University, Copenhagen, Denmark
- c Department of Clinical Biochemistry, Odense University Hospital, Odense, Denmark
- Correspondence to: O Wendelboe Nielsen
- Accepted 1 November 1999
Abstract
Objectives: To assess the probability of left ventricular systolic dysfunction without echocardiography in patients from general practice.
Design: Cross sectional study using multivariate regression models to examine the relation between clinical variables and left ventricular systolic dysfunction as determined by echocardiography.
Setting: Three general practices in Copenhagen.
Subjects: 2158 patients aged >40 years were screened by questionnaires and case record reviews; 357 patients with past or present signs or symptoms of heart disease were identified, of whom 126 were eligible for and consented to examination.
Main outcome measures: Clinical variables that were significantly (P<0.05) related to ejection fraction 0.45 and their predictive value for left ventricular systolic dysfunction.
Results: 15 patients (12%) had left ventricular systolic dysfunction. The prevalence was significantly related to three questions: does the electrocardiogram have Q waves, left bundle branch block, or ST-T segment changes? (P=0.012); is resting supine heart rate greater than the simultaneous diastolic blood pressure? (P=0.002); and is plasma N-terminal atrial natriuretic peptide>0.8 nmol/l? (P=0.040)? Only one of 60 patients with a normal electrocardiogram had systolic dysfunction (2%, 95% confidence interval 0% to 9%) regardless of response to the other two questions. The risk of dysfunction was appreciable in patients with a yes answer to two or three questions (50%, 27% to 73%).
Conclusions: A normal electrocardiogram implies a low risk of left ventricular systolic dysfunction. Patients can be identified for echocardiography on the basis of an abnormal electrocardiogram combined with increased natriuretic peptide concentration or a heart rate greater than diastolic blood pressure, or both.
Key messages
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Early treatment of left ventricular systolic dysfunction reduces morbidity, but diagnosis relies on echocardiography
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This study examines methods for assessing the risk of left ventricular systolic dysfunction in patients from primary care with past or present signs or symptoms of heart disease
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Risk can be assessed by three factors: QRS or ST-T changes in the electrocardiogram; increased plasma concentration of N-terminal atrial natriuretic peptide; and tachycardia (supine resting heart rate>diastolic blood pressure)
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Risk of systolic dysfunction was very low in patients with normal electrocardiographic results
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Risk was high in patients who had an abnormal electrocardiogram in combination with at least one other abnormal result
Footnotes
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Funding Danish Heart Foundation.
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Competing interests None declared.
- Accepted 1 November 1999
